U.S. patent application number 16/532632 was filed with the patent office on 2021-02-11 for system and method for identifying an emissions control failure in an indoor smoker.
The applicant listed for this patent is Haier US Appliance Solutions, Inc.. Invention is credited to Daniel Carballo, Tomas Garces.
Application Number | 20210037839 16/532632 |
Document ID | / |
Family ID | 1000004257791 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210037839 |
Kind Code |
A1 |
Garces; Tomas ; et
al. |
February 11, 2021 |
SYSTEM AND METHOD FOR IDENTIFYING AN EMISSIONS CONTROL FAILURE IN
AN INDOOR SMOKER
Abstract
An indoor smoker includes a smoking chamber and an air handler
for drawing a flow of smoke from the smoking chamber through an
exhaust duct. A catalytic converter is positioned in the exhaust
duct and includes a catalytic element and catalytic heater for
heating the catalytic element to a temperature suitable for
regulating emissions from the flow of smoke. A temperature sensor
is used to monitor the temperature of the catalytic element, and
smoke generation is stopped when the catalyst temperature drops
below a temperature threshold or drops at a rate that exceeds a
threshold rate, which may be indicative of a failure of the
catalyst heater or air handler.
Inventors: |
Garces; Tomas; (Louisville,
KY) ; Carballo; Daniel; (Louisville, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Haier US Appliance Solutions, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
1000004257791 |
Appl. No.: |
16/532632 |
Filed: |
August 6, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 53/8696 20130101;
B01D 53/885 20130101; A23V 2002/00 20130101; B01D 2258/0275
20130101; A23B 4/0523 20130101; B01D 53/8687 20130101; B01D
2257/708 20130101 |
International
Class: |
A23B 4/052 20060101
A23B004/052; B01D 53/88 20060101 B01D053/88; B01D 53/86 20060101
B01D053/86 |
Claims
1. An indoor smoker comprising: a cabinet defining a discharge
vent; a smoking chamber positioned within the cabinet and defining
a chamber outlet; an exhaust duct extending between the chamber
outlet and the discharge vent; an air handler fluidly coupled with
the exhaust duct for urging a flow of smoke from the smoking
chamber, through the exhaust duct, and out of the discharge vent; a
catalytic converter positioned within the exhaust duct, the
catalytic converter comprising a catalytic element and a catalyst
heater; a temperature sensor for detecting a catalyst temperature
of the catalytic element; and a controller in operative
communication with the temperature sensor, the controller being
configured for: measuring the catalyst temperature using the
temperature sensor; determining that an emissions control failure
has occurred based at least in part on the catalyst temperature;
and stopping the flow of smoke in response to determining that the
emissions control failure has occurred.
2. The indoor smoker of claim 1, wherein the emissions control
failure occurs when the catalyst temperature drops below a
temperature threshold.
3. The indoor smoker of claim 2, wherein the temperature threshold
is 700 degrees Fahrenheit.
4. The indoor smoker of claim 1, wherein the emissions control
failure occurs when the air handler or the catalyst heater stops
working properly.
5. The indoor smoker of claim 1, wherein the emissions control
failure occurs when a rate of change of the catalyst temperature
drops faster than a threshold rate.
6. The indoor smoker of claim 5, wherein the threshold rate is 100
degrees Fahrenheit per minute.
7. The indoor smoker of claim 1, further comprising: a smoke
generator for generating the flow of smoke, wherein stopping the
flow of smoke comprises disabling the smoke generator.
8. The indoor smoker of claim 7, wherein the smoke generator
comprises an auger that urges a combustible material past a
smoldering heater to generate the flow of smoke, and wherein
stopping the flow of smoke comprises advancing the auger of the
smoke generator to push the combustible material away from the
smoldering heater.
9. The indoor smoker of claim 7, wherein stopping the flow of smoke
comprises extinguishing the combustible material in a container of
water.
10. The indoor smoker of claim 7, wherein the combustible material
comprises wood chips, wood pellets, or wood resin.
11. The indoor smoker of claim 1, further comprising: a chamber
heater in thermal communication with the smoking chamber for
regulating a chamber temperature, wherein stopping the flow of
smoke comprises turning off the chamber heater.
12. The indoor smoker of claim 1, wherein the controller is further
configured for: notifying a user that the emissions control failure
has occurred.
13. The indoor smoker of claim 1, wherein the temperature sensor is
positioned downstream of the catalytic element.
14. The indoor smoker of claim 1, wherein the temperature sensor is
positioned between the catalytic element and the air handler.
15. The indoor smoker of claim 1, wherein the catalyst heater is
positioned upstream of the catalytic element.
16. A method of operating an indoor smoker, the indoor smoker
comprising an exhaust duct for extracting a flow of smoke from a
smoking chamber, a catalytic element positioned within the exhaust
duct for lowering volatile organic compounds within the flow of
smoke, and a temperature sensor for measuring a catalyst
temperature of the catalytic element, the method comprising:
measuring the catalyst temperature using the temperature sensor;
determining that an emissions control failure has occurred based at
least in part on the catalyst temperature; and stopping the flow of
smoke in response to determining that the emissions control failure
has occurred.
17. The method of claim 16, wherein the emissions control failure
occurs when the catalyst temperature drops below a temperature
threshold.
18. The method of claim 16, wherein the emissions control failure
occurs when a rate of change of the catalyst temperature drops
faster than a threshold rate.
19. The method of claim 16, further comprising: a smoke generator
for generating the flow of smoke, wherein stopping the flow of
smoke comprises disabling the smoke generator.
20. The method of claim 16, further comprising: notifying a user
that the emissions control failure has occurred.
Description
FIELD OF THE INVENTION
[0001] The present subject matter relates generally to indoor
smokers, and more particularly to systems and methods of smoke and
emissions regulation in indoor smokers.
BACKGROUND OF THE INVENTION
[0002] Conventional smokers include a smoking chamber and a firebox
positioned within or fluidly coupled to the smoking chamber. The
firebox is filled with a combustible material, such as wood or wood
byproducts that are ignited or otherwise heated to generate smoke
and/or heat. The heat and smoke are routed into the smoking chamber
to impart flavor on and cook food items positioned within the
smoking chamber. One or more heating elements may be positioned
within the smoking chamber and the firebox to maintain the
temperatures necessary both for cooking the food and for generating
the desired amount of smoke.
[0003] Conventional smokers are used outdoors and simply exhaust
smoke directly outside through a chimney or vent. Notably, such
smoke frequently contains harmful byproducts of the combusted fuel,
such as volatile organic compounds (VOCs) or other harmful
emissions. These byproducts, as well as the large amount of smoke
generated by the combusted fuel, generally prohibit the use of
smokers inside the home. Although fume hoods or exhaust systems may
be used to route the smoke from indoors to outdoors, such systems
would be complex, costly, and frequently not practical or
effective.
[0004] Catalysts may be used to help regulate or reduce harmful
emissions from smoke generated in indoor smokers, but such
catalysts typically require that the catalyst material be heated to
a suitably high temperature in order to effectively eliminate
byproducts of the smoldering process such as carbon monoxide. In
the event of a failure of one or more system components, the
temperature of the catalyst may drop below a suitable threshold
temperature, at which point unregulated and harmful emissions may
enter freely into the room where the indoor smoker is located.
[0005] Accordingly, a smoker that has features for permitting safe
indoor use would be useful. More specifically, an indoor smoker
with a catalytic converter system that includes failure detection
features would be particularly beneficial.
BRIEF DESCRIPTION OF THE INVENTION
[0006] Aspects and advantages of the invention will be set forth in
part in the following description, may be apparent from the
description, or may be learned through practice of the
invention.
[0007] In one aspect of the present disclosure, an indoor smoker is
provided including a cabinet defining a discharge vent, a smoking
chamber positioned within the cabinet and defining a chamber
outlet, and an exhaust duct extending between the chamber outlet
and the discharge vent. An air handler is fluidly coupled with the
exhaust duct for urging a flow of smoke from the smoking chamber,
through the exhaust duct, and out of the discharge vent, and a
catalytic converter is positioned within the exhaust duct, the
catalytic converter including a catalytic element and a catalyst
heater. A temperature sensor detects a catalyst temperature of the
catalytic element and a controller is in operative communication
with the temperature sensor for measuring the catalyst temperature
using the temperature sensor, determining that an emissions control
failure has occurred based at least in part on the catalyst
temperature, and stopping the flow of smoke in response to
determining that the emissions control failure has occurred.
[0008] In another aspect of the present disclosure, a method of
operating an indoor smoker is provided. The indoor smoker includes
an exhaust duct for extracting a flow of smoke from a smoking
chamber, a catalytic element positioned within the exhaust duct for
lowering volatile organic compounds within the flow of smoke, and a
temperature sensor for measuring a catalyst temperature of the
catalytic element. The method includes measuring the catalyst
temperature using the temperature sensor, determining that an
emissions control failure has occurred based at least in part on
the catalyst temperature, and stopping the flow of smoke in
response to determining that the emissions control failure has
occurred.
[0009] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures.
[0011] FIG. 1 provides a perspective view of an indoor smoker with
a door in a closed position in accordance with an example
embodiment of the present disclosure.
[0012] FIG. 2 provides a perspective view the exemplary indoor
smoker of FIG. 1 with the door opened.
[0013] FIG. 3 provides a schematic, top cross-sectional view of the
exemplary indoor smoker of FIG. 1 according to an exemplary
embodiment of the present subject matter.
[0014] FIG. 4 is a plot of a catalyst temperature in the event of a
blower or catalyst heater failure according to an exemplary
embodiment of the present subject matter.
[0015] FIG. 5 is a method of operating an indoor smoker according
to an example embodiment of the present subject matter.
[0016] Repeat use of reference characters in the present
specification and drawings is intended to represent the same or
analogous features or elements of the present invention.
DETAILED DESCRIPTION
[0017] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0018] As used herein, the terms "upstream" and "downstream" refer
to the relative direction with respect to fluid flow in a fluid
pathway. For example, "upstream" refers to the direction from which
the fluid flows, and "downstream" refers to the direction to which
the fluid flows. In addition, as used herein, terms of
approximation, such as "approximately," "substantially," or
"about," refer to being within a ten percent margin of error.
Furthermore, the term "smoke" is generally used to refer to the
flow of air, smoke, combustion byproducts, or any combination
thereof through an appliance.
[0019] FIGS. 1 and 2 provide perspective views of an indoor smoker
100 according to an exemplary embodiment of the present subject
matter with the door in the closed position and the open position,
respectively. Indoor smoker 100 generally defines a vertical
direction V, a lateral direction L, and a transverse direction T,
each of which is mutually perpendicular, such that an orthogonal
coordinate system is generally defined. As illustrated, indoor
smoker 100 includes an insulated cabinet 102. Cabinet 102 of indoor
smoker 100 extends between a top 104 and a bottom 106 along the
vertical direction V, between a first side 108 (left side when
viewed from front) and a second side 110 (right side when viewed
from front) along the lateral direction L, and between a front 112
and a rear 114 along the transverse direction T.
[0020] Within cabinet 102 is a smoking chamber 120 which is
configured for the receipt of one or more food items to be cooked
and/or smoked. In general, smoking chamber 120 is at least
partially defined by a plurality of chamber walls 122.
Specifically, smoking chamber 120 may be defined by a top wall, a
rear wall, a bottom wall, and two sidewalls. These chamber walls
122 may define smoking chamber 120 and an opening through which a
user may access food articles placed therein. In addition, chamber
walls 122 may be joined, sealed, and insulated to help retain smoke
and heat within smoking chamber 120. In this regard, for example,
in order to insulate smoking chamber 120, indoor smoker 100
includes an insulating gap defined between chamber walls 122 and
cabinet 102. According to an exemplary embodiment, the insulation
gap is filled with insulating material (not shown), such as
insulating foam or fiberglass.
[0021] Indoor smoker 100 includes a door 126 rotatably attached to
cabinet 102 in order to permit selective access to smoking chamber
120. A handle 128 is mounted to door 126 to assist a user with
opening and closing door 126 and a latch 130 is mounted to cabinet
102 for locking door 126 in the closed position during a cooking or
smoking operation. In addition, door 126 may include one or more
transparent viewing windows 132 to provide for viewing the contents
of smoking chamber 120 when door 126 is closed and also to assist
with insulating smoking chamber 120.
[0022] Referring still to FIGS. 1 and 2, a user interface panel 134
and a user input device 136 may be positioned on an exterior of
cabinet 102. User interface panel 134 may represent a general
purpose Input/Output ("GPIO") device or functional block. In some
embodiments, user interface panel 134 may include or be in
operative communication with user input device 136, such as one or
more of a variety of digital, analog, electrical, mechanical or
electro-mechanical input devices including rotary dials, control
knobs, push buttons, and touch pads. User input device 136 is
generally positioned proximate to user interface panel 134, and in
some embodiments, user input device 136 may be positioned on user
interface panel 134. User interface panel 134 may include a display
component 138, such as a digital or analog display device designed
to provide operational feedback to a user.
[0023] Generally, indoor smoker 100 may include a controller 140 in
operative communication with user input device 136. User interface
panel 134 of indoor smoker 100 may be in communication with
controller 140 via, for example, one or more signal lines or shared
communication busses, and signals generated in controller 140
operate indoor smoker 100 in response to user input via user input
devices 136. Input/Output ("I/O") signals may be routed between
controller 140 and various operational components of indoor smoker
100 such that operation of indoor smoker 100 can be regulated by
controller 140.
[0024] Controller 140 is a "processing device" or "controller" and
may be embodied as described herein. Controller 140 may include a
memory and one or more microprocessors, microcontrollers,
application-specific integrated circuits (ASICS), CPUs or the like,
such as general or special purpose microprocessors operable to
execute programming instructions or micro-control code associated
with operation of indoor smoker 100, and controller 140 is not
restricted necessarily to a single element.
[0025] The memory may represent random access memory such as DRAM,
or read only memory such as ROM, electrically erasable,
programmable read only memory (EEPROM), or FLASH. In one
embodiment, the processor executes programming instructions stored
in memory. The memory may be a separate component from the
processor or may be included onboard within the processor.
Alternatively, controller 140 may be constructed without using a
microprocessor, e.g., using a combination of discrete analog and/or
digital logic circuitry (such as switches, amplifiers, integrators,
comparators, flip-flops, AND gates, and the like) to perform
control functionality instead of relying upon software.
[0026] Although aspects of the present subject matter are described
herein in the context of an indoor smoker having a single smoking
chamber, it should be appreciated that indoor smoker 100 is
provided by way of example only. Other smoking appliances having
different configurations, different appearances, and/or different
features may also be utilized with the present subject matter,
e.g., outdoor smokers, conventional oven appliances, or other
suitable cooking appliances. Thus, the example embodiment shown in
FIG. 1 is not intended to limit the present subject matter to any
particular smoking configuration or arrangement. Moreover, aspects
of the present subject matter may be used in any other consumer or
commercial appliance where it is desirable to regulate a flow of
smoke or harmful emissions in an appliance.
[0027] Referring now also to FIG. 3, various internal components of
indoor smoker 100 and their respective functions will be described
according to an exemplary embodiment of the present subject matter.
In this regard, FIG. 3 illustrates a schematic top cross-sectional
view of indoor smoker 100 of FIG. 1. As shown, indoor smoker 100
generally includes smoking chamber 120 for receiving items to be
cooked/smoked, a smoke generating device or smoke generator 150 for
generating smoke, and an exhaust system 154 for safely discharging
that the air and/or smoke into an indoor environment 156 (i.e.,
outside of indoor smoker 100). Each of these systems and components
will be described in detail below.
[0028] Referring still to FIG. 3, smoke generator 150 generally
defines a smoldering chamber 160 which is configured for receiving
combustible material 162. As used herein, "combustible material" is
generally used to refer to any suitable material positioned within
smoldering chamber 160 for generating smoke. Specifically,
according to exemplary embodiments, combustible material 162
includes wood or wood byproducts, such as wood chunks, wood chips,
wood pellets, or wood resin. According to the exemplary embodiment,
smoke generator 150 may include a door or another access panel (not
shown) for providing selective access to smoldering chamber 160,
e.g., to add additional combustible material 162.
[0029] As best illustrated in FIG. 3, smoke generator 150 defines
an air inlet 164 for receiving air to support the combustion or
smoldering process. Specifically, air inlet 164 is configured for
receiving a flow of combustion air (indicated by reference numeral
166 in FIG. 3) from the ambient environment 156 surrounding indoor
smoker 100 or from another air supply source. During a smoking
process, combustible material 162 is ignited and the flow of
combustion air 166 supports the smoldering process to generate a
flow of smoke (indicated by reference numeral 168 in FIG. 3). Smoke
generator 150 further defines a smoke outlet 170 for providing a
flow of smoke 168 into smoking chamber 120 during a smoking
operation, as will be described in detail below.
[0030] Indoor smoker 100 further includes an air handler 172 for
urging the flow of combustion air 166 into smoldering chamber 160
through air inlet 164 for facilitating the smoldering process and
smoke generating process. In addition, indoor smoker 100 may
further include features for preventing or regulating the flow of
combustion air 166 from entering indoor smoker 100 from environment
156 when the flow of such air is not desired. In this regard, for
example, indoor smoker 100 may include an inlet check valve 174
which is operably coupled to air inlet 164. In general, this check
valve prevents the flow of combustion air 166 from entering
smoldering chamber 160 when not desired.
[0031] For example, inlet check valve 174 may have a "cracking
pressure," which is used herein to refer to the pressure, or more
precisely the negative pressure, required within smoldering chamber
160 to open inlet check valve 174. In this manner, inlet check
valve 174 may be designed to permit the flow of combustion air 166
only when air handler 172 is operating and urging air through
smoldering chamber 160, thus facilitating the quick and effective
asphyxiation of combustible material 162 within smoldering chamber
160 when desired.
[0032] Referring still to FIG. 3, smoke generator 150 includes one
or more smoldering heaters 176 which are positioned in smoldering
chamber 160 or otherwise placed in thermal communication with
combustible material 162 stored in smoldering chamber 160 for
smoldering combustible material 162. According to an exemplary
embodiment, smoldering heater 176 may include one or more cartridge
heaters or silicon nitride igniters. Alternatively, smoldering
heater 176 may include any other suitable type, position, and
configuration of heating elements. As used herein, the term
"heating element," "heaters," and the like may generally refer to
electric resistance heating elements, gas burners, microwave
heating elements, halogen heating elements, or suitable
combinations thereof.
[0033] As used herein, the verb "smolder" or variations thereof is
intended to refer to burning a combustible material (e.g.,
combustible material 162) slowly such that smoke is generated but
little or no flame is generated. In this manner, the combustible
material is not expended quickly, but a large amount of smoke is
generated for the smoking process. Notably, the burn rate of
combustible material and the amount of smoke generated is regulated
using smoldering heater 176 positioned within smoldering chamber
160. For typical combustible material used in smokers, e.g., wood
and wood byproducts, a typical smoldering temperature is between
about 650.degree. F. and 750.degree. F. However, the exact
temperature may vary depending on the combustible material used,
the air flow rate through smoldering chamber 160, the level of
combustible material 162, and other factors.
[0034] According to the illustrated embodiment, smoke generator 150
extends between a first end 178 proximate to air inlet 164 and a
second and 180 positioned proximate smoke outlet 170. As shown,
smoldering heater 176 is positioned proximate second end 180, e.g.,
immediately adjacent smoke outlet 170. Smoke generator 150 further
includes a rotating auger 182 that is mounted within smoldering
chamber 160 and generally rotates about a central axis 184. In this
manner, as rotating auger 182 rotates, combustible material 162
positioned within smoldering chamber 160 is slowly but
progressively advanced past smoldering heater 176.
[0035] After combustible material 162 positioned near smoldering
heater 176 is completely consumed or smoldered, rotating auger 182
may rotate to advance the consumed material toward a discharge port
186 positioned at second end 180 of smoke generator 150. According
to an exemplary embodiment, a container of water 188 may be
positioned below discharge port 186 such that used combustible
material 162 may fall therein and immediately extinguish. According
to alternative embodiments, consumed combustible material 162 may
be discharged in any other suitable manner into to any other
suitable container or reservoir.
[0036] In order to ensure a desirable cooking temperature within
smoking chamber 120, indoor smoker 100 further includes a chamber
heater 190 that is positioned within or otherwise in thermal
communication with smoking chamber 120 for regulating the
temperature in smoking chamber 120. In general, chamber heater 190
may include one or more heating elements positioned within cabinet
102 for selectively heating smoking chamber 120. For example, the
heating elements may be electric resistance heating elements, gas
burners, microwave heating elements, halogen heating elements, or
suitable combinations thereof. Notably, because chamber heater 190
is operated independently of smoke generator 150 (e.g., as
described below), smoking chamber 120 may be maintained at any
suitable temperature during a smoking process. More specifically,
for example, chamber heater 190 may be turned off or on a very low
setting for smoking cheeses or may be turned on high for quickly
cooking and smoking meats.
[0037] In some embodiments, indoor smoker 100 also includes one or
more sensors that may be used to facilitate improved operation of
the appliance, such as described below. For example, indoor smoker
100 may include one or more temperature sensors and/or humidity
sensors which are generally operable to measure the internal
temperature and humidity in indoor smoker 100, e.g., within smoking
chamber 120 and/or smoldering chamber 160. More specifically, as
illustrated, indoor smoker 100 includes a temperature sensor 192
and a humidity sensor 194 positioned within smoking chamber 120 and
being operably coupled to controller 140. In some embodiments,
controller 140 is configured to vary operation of chamber heater
190 based on one or more temperatures detected by temperature
sensor 192 or humidity measurements from humidity sensor 194.
[0038] As described herein, "temperature sensor" may refer to any
suitable type of temperature sensor. For example, the temperature
sensors may be thermocouples, thermistors, or resistance
temperature detectors. Similarly, "humidity sensor" may refer to
any suitable type of humidity sensor, such as capacitive digital
sensors, resistive sensors, and thermal conductivity humidity
sensors. In addition, temperature sensor 192 and humidity sensor
194 may be mounted at any suitable location and in any suitable
manner for obtaining a desired temperature or humidity measurement,
either directly or indirectly. Although exemplary positioning of
certain sensors is described below, it should be appreciated that
indoor smoker 100 may include any other suitable number, type, and
position of temperature and/or humidity sensors according to
alternative embodiments.
[0039] As mentioned briefly above, indoor smoker 100 further
includes an exhaust system 154 which is generally configured for
safely discharging the flow of smoke 168 from indoor smoker 100.
Specifically, according to the illustrated embodiment, exhaust
system 154 generally extends between a chamber outlet 200 and a
discharge vent 202 defined by cabinet 102 for directing the flow of
smoke 168 from smoking chamber 120 to the environment 156. Although
an exemplary exhaust system 154 is described below, it should be
appreciated that variations and modifications may be made while
remaining within the scope of the present subject matter. For
example, the routing of ducts, the catalytic converter arrangement,
and the types of sensors used may vary according to alternative
embodiments.
[0040] As shown, exhaust system 154 includes an exhaust duct 204
that generally extends between and provides fluid communication
between chamber outlet 200 and discharge vent 202. Air handler 172
is operably coupled with exhaust duct 204 for urging the flow of
smoke 168 through exhaust duct 204 and out of discharge vent 202 to
environment 156. According to the illustrated exemplary embodiment,
air handler 172 is a centrifugal fan positioned within exhaust duct
204. However, it should be appreciated that according to
alternative embodiments, air handler 172 may be positioned at any
other suitable location and may be any other suitable fan type,
such as a tangential fan, an axial fan, etc.
[0041] In addition, according to an exemplary embodiment, air
handler 172 is a variable speed fan such that it may rotate at
different rotational speeds, thereby generating different air flow
rates. In this manner, the amount of smoke drawn from smoldering
chamber 160 may be continuously and precisely regulated. Moreover,
by pulsing the operation of air handler 172 or throttling air
handler 172 between different rotational speeds, the flow of smoke
168 drawn into smoking chamber 120 may enter from a different
direction, may have a different flow velocity, or may generate a
different flow pattern within smoking chamber 120. Thus, by
pulsating the variable speed fan or otherwise varying its speed,
the flow of smoke 168 may be randomized, thereby eliminating
stagnant regions within smoking chamber 120 and better circulating
the flow of smoke 168 to provide a more even cooking/smoking
profile.
[0042] As illustrated, indoor smoker 100 further includes a
catalytic converter 210 which is positioned within exhaust duct 204
for lowering or removing volatile organic compounds (VOCs) from the
flow of smoke 168. As used herein, "catalytic converter" or
variations thereof may be used to refer to any component, machine,
or device that is configured for removing or lowering volatile
organic compounds (VOCs), toxic gases, harmful emissions,
pollutants, or undesirable compounds from a flow of air and smoke.
For example, according to the illustrated embodiment, catalytic
converter 210 generally includes a catalytic element 212 and a
catalyst heater 214.
[0043] In general, catalytic element 212 includes a material that
causes an oxidation and a reduction reaction. For example, precious
metals such as platinum, palladium, and rhodium are commonly used
as catalyst materials, though other catalysts are possible and
within the scope of the present subject matter. In operation, the
catalytic element 212 may combine oxygen (O.sub.2) with carbon
monoxide (CO) and unburned hydrocarbons to produce carbon dioxide
(CO.sub.2) and water (H.sub.2O). In addition, according to
exemplary embodiments, catalytic element 212 may remove nitric
oxide (NO) and nitrogen dioxide (NO.sub.2).
[0044] Notably, catalytic converters typically require that the
catalyst be heated to a suitably high temperature in order to
catalyze the necessary chemical reactions. Therefore, catalyst
heater 214 is in thermal communication with catalytic element 212
for heating it to a suitable temperature, such as approximately
800.degree. F. According to the illustrated embodiment, catalyst
heater 214 is positioned upstream of catalytic element 212 to
provide thermal energy through convection. However, it should be
appreciated that according to alternative embodiments, catalyst
heater 214 may be in direct contact with catalytic element 212 to
provide thermal energy through conduction, or may be thermally
coupled to catalytic element 212 in any other suitable manner.
[0045] In order to ensure a catalyst temperature of catalytic
element 212 remains above a temperature suitable for controlling
emissions, indoor smoker 100 may further include a catalyst
temperature sensor 216 that is in thermal communication with
catalytic element 212 for monitoring the catalyst temperature. For
example, an exemplary temperature profile of catalytic element 212
is illustrated in FIG. 4. As will be described below, controller
140 may be in operative communication with temperature sensor 216
and may provide corrective action or a user notification in the
event that the catalyst temperature falls outside of the desired
range, e.g., indicating an emissions control failure identified in
FIG. 4 by reference numeral 218.
[0046] Notably, temperature sensor 216 may generally be positioned
at any suitable location for determining an effective temperature
of catalytic element 212. In this regard, the measured catalyst
temperature is preferably a catalyst temperature that corresponds
with or is indicative of the amount of VOCs or emissions that may
be removed from a flow of smoke. According to the illustrated
embodiment, temperature sensor 216 is positioned at a downstream
end of catalytic element 212, e.g., between catalytic element 212
and air handler 172. In addition, catalyst heater 214 is positioned
upstream of catalytic element 212, e.g., to heat the flow of smoke
168 prior to entering catalytic element 212 in order to raise the
temperature of catalytic element 212. It should be appreciated that
other temperature sensor positions and catalytic converter
configurations may be used while remaining within the scope of the
present subject matter.
[0047] Thus, during operation of indoor smoker 100, air handler 172
draws the flow of combustion air 166 into smoldering chamber 160
through air inlet 164. The flow of combustion air 166 and
combustible material 162 in the smoldering chamber 160 generate the
flow of smoke 168 which is drawn into smoking chamber 120 as
described below. The flow of smoke 168 passes through smoking
chamber 120 for performing a smoking process on food items
positioned therein before exiting smoking chamber 120 through
chamber outlet 200. Air handler 172 then continues to urge the flow
of smoke 168 through catalytic converter 210 and exhaust duct 204
before passing out discharge vent 202.
[0048] Now that the construction and configuration of indoor smoker
100 has been described according to an exemplary embodiment of the
present subject matter, an exemplary method 300 for regulating a
flow of air and/or smoke within or otherwise operating an indoor
smoker will be described according to an exemplary embodiment of
the present subject matter. Method 300 can be implemented by
controller 140 and may be used to operate indoor smoker 100, or any
other smoker or cooking appliance. It should be appreciated that
the exemplary method 300 is discussed herein only to describe
exemplary aspects of the present subject matter, and is not
intended to be limiting.
[0049] Referring now to FIG. 5, method 300 includes, at step 310,
exhausting a flow of smoke from a smoking chamber of an indoor
smoker through an exhaust duct containing a catalytic element. In
this regard, according to the embodiment described above, the flow
of smoke 168 within smoking chamber 120 of indoor smoker 100 may be
withdrawn or evacuated through exhaust duct 202 using air handler
172. Notably, as explained above, catalyst heater 214 is generally
configured for heating the flow of smoke 168 to maintain catalytic
element 212 at a temperature suitable for reducing emissions within
the flow of smoke 168.
[0050] Notably, in the event of a failure of one or more system
components, particularly those components related to exhaust system
154, the temperature of catalytic element 212 may not be suitable
for removing harmful emissions or contaminants from the flow of
smoke 168. When such a failure occurs, the flow of smoke 168 may
pass through catalytic converter 210 and out discharge vent 202
without having harmful VOCs or emissions removed. For example, if
catalyst heater 214 fails for any reason, air handler 172 may
continue to draw the flow of smoke 168 from smoking chamber 120
through catalytic converter 210, but the catalytic converter 210
will no longer be heated such that harmful emissions remain within,
and are exhausted with, the flow of smoke 168. By contrast, if air
handler 172 fails, catalyst heater 214 will only keep an upstream
end of catalytic element 212 heated, while downstream end of
catalytic element 212 remains relatively cool, e.g., because the
flow of heated smoke is not drawn through catalytic element 212. In
either instance, it may be desirable to stop the production of the
flow of smoke 168 or to otherwise isolate smoking chamber 120 to
prevent harmful VOCs from escaping into environment 156.
[0051] Thus, step 320 includes measuring a catalyst temperature
using a temperature sensor positioned in thermal communication with
the catalytic element. For example, FIG. 4 provides a plot of
catalyst temperature measurements throughout a smoking process
according to an exemplary embodiment. By monitoring this catalyst
temperature, controller 140 may make determinations as to the
operation and performance of indoor smoker 100, and can take
corrective action in the event of dangerous or undesirable
conditions.
[0052] For example, step 330 includes determining that an emissions
control failure has occurred based at least in part on the catalyst
temperature. As used herein, "emissions control failure" is
intended to refer to any condition or situation where a flow of
smoke is being generated by an indoor smoker while an emissions
control system (e.g., such as catalytic converter 210) is not
operating as required to remove harmful emissions or contaminants
from that flow of smoke. For example, according to exemplary
embodiments, an emissions control failure with respect to indoor
smoker 100 may include the failure of air handler 172 and/or
catalyst heater 214.
[0053] According to exemplary embodiments, the occurrence of an
emissions control failure may be determined based on an absolute
temperature of catalytic element 212. In this regard, for example,
if the catalyst temperature drops below a predetermined temperature
threshold, an emissions control failure may be triggered and
corrective action may be taken. According to an exemplary
embodiment, the predetermined temperature threshold may be between
about 500.degree. F. and 800.degree. F., between about 600.degree.
F. and 700.degree. F., or approximately 650.degree. F. It should be
appreciated that the predetermined temperature may vary based on a
variety of factors, including catalyst material, smoke flow rates,
etc.
[0054] According to another exemplary embodiment, the occurrence of
an emissions control failure may be determined based on a rate of
change of the catalyst temperature. For example, if the rate of
change of the catalyst temperature drops faster than a
predetermined threshold rate, an emissions control failure may be
triggered. According to an exemplary embodiment, the threshold rate
may be between about 25.degree. F. and 200.degree. F. per minute,
between about 75.degree. F. and 125.degree. F. per minute, or
approximately 100.degree. F. per minute. Other threshold rates are
possible and remain within the scope of the present subject
matter
[0055] Step 340 includes stopping the flow of smoke in response to
determining that an emissions control failure has occurred. For
example, if controller 140 detects that catalyst temperature has
dropped below the temperature threshold (e.g., 650.degree. F.), or
if the catalyst temperature is dropping at a rate that exceeds a
threshold rate (e.g., 100.degree. F./minute), controller 140 may
determine that it is not safe to generate additional smoke and may
shut down indoor smoker 100 to prevent the flow of smoke 168.
[0056] In general, indoor smoker 100 may be configured for stopping
the flow of smoke in accordance with step 340 in any suitable
manner. For example, smoke generator 150 may be sealed off or
extinguished to prevent smoke generation. According to an exemplary
embodiment, rotating auger 182 may rotate to advance combustible
material 162 out of smoldering chamber 160 and into the container
of water 188. In this manner, the water may immediately extinguish
combustible material to prevent further smoke generation. In
addition, smoldering heater 176 and/or chamber heater 190 may be
turned off. According still other embodiments, indoor smoker 100
may include one or more dampers (not shown) that are configured to
seal off smoking chamber 120 or smoldering chamber 160 in the event
of an emissions control failure.
[0057] In addition, step 350 may include notifying a user that the
emissions control failure has occurred. In this manner, a user may
be informed of such a failure so that corrective action may be
implemented. According to an exemplary embodiment, the user
notification may be provided via display 138 or in any other
suitable manner. In this regard, controller 140 may trigger a
particular message on display 138 or may illuminate an indicator
light to inform a user that service is needed. According to still
other embodiments, controller 140 may communicate with a remote
server, an external network, and/or a remote device such as a
mobile phone to provide such indication.
[0058] FIG. 5 depicts an exemplary method having steps performed in
a particular order for purposes of illustration and discussion.
Those of ordinary skill in the art, using the disclosures provided
herein, will understand that the steps of any of the methods
discussed herein can be adapted, rearranged, expanded, omitted, or
modified in various ways without deviating from the scope of the
present disclosure. Moreover, although aspects of the methods are
explained using indoor smoker 100 as an example, it should be
appreciated that these methods may be applied to regulate smoke in
any other smoking appliance.
[0059] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *